Systems for generating digital models of patient teeth

ABSTRACT

Systems for modeling a patient&#39;s teeth are provided. In some embodiments, a system includes a scanner operable to capture a scanned image of at least a portion of a surface of a first crown component of a first patient tooth, and to generate scanned image data representing a partial portion of the surface of the first crown component. The system can also include a processor configured to create a digital data set representing the scanned image data, select a digital tooth template that includes a second digital crown portion corresponding to the scanned image, create a morphed digital tooth crown model based on the selected digital tooth template, and merge the morphed digital tooth crown model with the digital data set representing the scanned image data of the first patient tooth to generate a complete digital patient tooth crown model.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/924,960, filed on Jun. 24, 2013, now U.S. Pat. No. 10,789,394; whichis a continuation of U.S. patent application Ser. No. 13/558,038, filedon Jul. 25, 2012, now U.S. Pat. No. 8,478,435; which is a divisional ofU.S. patent application Ser. No. 12/961,818, filed on Dec. 7, 2010, nowU.S. Pat. No. 8,244,390; which is a divisional of U.S. patentapplication Ser. No. 11/951,812, filed on Dec. 6, 2007, now U.S. Pat.No. 7,865,259. The disclosures of all of the foregoing applications arehereby incorporated herein by reference in their entireties.

BACKGROUND 1. Field of the Invention

The present invention relates, generally, to dental and/or orthodontictreatment, and in particular to a system and method for modeling acomplete tooth of a patient to facilitate dental and/or orthodontictreatment.

2. Related Art

Current techniques for impression-based computational orthodontics arebased on impressions, three dimensional (3-D) radiographic scans or 3-Dx-rays of teeth, which capture the surface of the teeth. Unfortunately,when two or more teeth are in close proximity, the digital datarepresenting surfaces of the individual teeth are difficult to separatewhen using these techniques. The same problem exists for “unerupted”teeth, where the initial scan may capture only exposed portions of theteeth.

The inability to account accurately for the interproximal and uneruptedsurfaces of the teeth means that aligners created based on theincomplete data may not properly fit in the areas that are later exposedeither through eruption from the gingiva, uncrowding, or improvedhygiene, which may firm up the gingival tissue and expose more toothstructure. An aligner that does not fit well becomes less effective inlater stages of the orthodontic treatment. A poorly fitting aligner mayalso compromise the esthetics of the appliance, which in turn, may leadto suboptimal patient compliance in wearing the aligners.

SUMMARY

In accordance with various aspects of the present invention, a systemand method are provided to account for the interproximal and uneruptedsurfaces of teeth that are partially blocked or unexposed inimpressions, 3-D radiographic scans or 3-D X-rays to facilitate dentaland/or orthodontic treatment.

In one aspect, a digital data set representing a pre-scanned toothgeometry, including generic crown data, is merged with data representinga scanned patient tooth crown image, which lacks sufficient data tocompletely represent a complete tooth crown.

This brief summary has been provided so that the nature of the inventionmay be understood quickly. A more complete understanding of theinvention may be obtained by reference to the following detaileddescription in connection with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features and other features of the present invention willnow be described with reference to the drawings. In the drawings, thesame components have the same reference numerals. The illustratedembodiment is intended to illustrate, but not to limit the invention.The drawings include the following Figures:

FIG. 1A is a flow diagram of a process for creating a complete toothmodel from tooth images of teeth having partially blocked or unexposedsurfaces in accordance with an embodiment of the present invention;

FIG. 1B is composed of images illustrating the process of FIG. 1A forcreating a complete tooth model from tooth images of teeth havingpartially blocked or unexposed surfaces in accordance with an embodimentof the present invention;

FIG. 1C illustrates a system for implementing the process of FIGS. 1Aand 1B in accordance with an embodiment of the present invention;

FIG. 2 is a flow diagram illustrating a computer-implemented process formodeling of a complete tooth crown model of a patient's partiallyblocked or unexposed crown surfaces in accordance with an embodiment ofthe present invention;

FIGS. 3A-3C illustrate a flow diagram and graphical representations ofan exemplary method of modeling a generic teeth template in accordancewith an exemplary embodiment of the present invention;

FIGS. 4A-4D illustrate a flow diagram and graphical representations ofan exemplary method of automatic landmark generation for tooth crown inaccordance with an embodiment of the present invention;

FIGS. 5A and 5B illustrate a flow diagram and a graphical representationfor an exemplary method for root and crown mesh generation in accordancewith an exemplary embodiment of the present invention;

FIG. 6 illustrates a flow diagram for an exemplary method for meshing ofthe generic crown with the patient crown in accordance with anembodiment of the present invention; and

FIGS. 7A-7F illustrate an exemplary flow diagram and graphicalrepresentations for automatic complete tooth model adjustment usingX-ray data in accordance with an exemplary embodiment of the presentinvention.

DETAILED DESCRIPTION

The present invention may be described herein in terms of variouscomponents and processing steps. It should be appreciated that suchcomponents and steps may be realized by any number of hardware andsoftware components configured to perform the specified functions. Forexample, the present invention may employ various electronic controldevices, visual display devices, input terminals and the like, which maycarry out a variety of functions under the control of one or morecontrol systems, microprocessors or other control devices.

In addition, the present invention may be practiced in any number oforthodontic or dental contexts and the exemplary embodiments relating toa system and method for modeling of complete tooth of a patient asdescribed herein are merely a few of the exemplary applications for theinvention. For example, the principles, features and methods discussedmay be applied to any orthodontic or dental treatment application orprocess.

For illustrative purposes, the various exemplary methods and systems maybe described in connection with a single tooth of a patient; however,such exemplary methods and systems may be implemented on more than onetooth and/or all teeth within a patient, such as molars, bicuspids,canines, incisors or any other teeth. For example, the exemplary methodsand systems may be implemented by performing a particular process,operation or step on one or more teeth before proceeding to a subsequentprocess, operation or step, or by performing all or essentially allprocesses, operations or steps on a particular tooth before proceedingto another tooth, or any combination thereof.

In one embodiment, the present invention includes taking a digital dataset representing a scanned typodont tooth geometry and using the data bycombining or merging the data with digital data representing a partiallyerupted or partially blocked tooth crown. By using the two sets of databy, for example, digitally combining or merging the digital typodonttooth model to the digital scanned tooth crown model, the blocked orunexposed surfaces of the patient crown may be completed using thetypodont tooth geometry to “fill-in” the missing tooth crown surface.Such a process may be applied for any and all of the various teethwithin a patient, such as molars, bicuspids, canines, incisors or anyother teeth.

In another embodiment of the invention, a digital data set representinga scanned tooth of the patient from the contralateral side is digitallymirrored and combined or merged with data representing a scanned toothcrown image which lacks sufficient data to completely represent acomplete tooth crown.

In another embodiment of the invention, a digital data set representinga scanned tooth of a patient having similar dentition is combined withdata representing a scanned tooth crown image which lacks sufficientdata to completely represent a complete tooth crown.

In another embodiment, the present invention includes taking the digitaldata set representing a similar tooth but from a different patient andcombining or merging the data with data representing a scanned toothcrown image which lacks sufficient data to completely represent acomplete tooth crown.

Such modeling techniques may be conducted with one or morecomputer-based systems, such as systems configured for storing actualpatient data and generic tooth data, morphing generic tooth data to suchpatient's data and/or facilitating additional orthodontic treatmentapplications, through the use of one or more algorithms.

FIGS. 1A and 1B illustrate a process 100 for creating a complete toothmodel in a digital format from tooth images that are created from teethhaving partially blocked or unexposed surfaces in accordance with thepresent invention. In one embodiment, process 100 includes a typodonttooth geometry module 102 for creating a digital data set representing ageneric typodont, including crown geometry and, optionally rootgeometry, such as generic tooth model 104 (FIG. 1B). Process 100 alsoincludes patient tooth image module 106 for creating a digital data setrepresenting a surface image of a crown of a patient with an incompletesurface portion, such as patient tooth crown 108. In complete toothmodel module 110 the typodont tooth surface geometry data set generatedin module 102 is “combined” or “merged,” (also “morphed” or “stitched”)to the patient's incomplete surface image data set generated in module106 to yield a complete tooth image data set, such as 3-D complete toothmodel 112.

In one embodiment, further adjustment of the complete tooth model 112may be provided through detailed adjustment module 114. For example,additional patient information regarding the actual crown of a patientmay be obtained, such as from 3-D radiographic images 116 and the like.The scanned images may be used as the basis for morphing geometries tothe scanned images to address variations in tooth shape between thegeneric tooth 104 and the partially represented actual tooth shape 108so as to yield a tooth shape on complete tooth model 112 which moreclosely approximates the actual tooth.

In typodont tooth geometry module 102, a generic typodont tooth surfacegeometry model (which may include a generic root structure) may bescanned using well known destructive scanning techniques, to provide thedigital data representing the generic typodont tooth surface geometry.Typically, the generic typodont tooth surface geometry data representsthe same type of tooth (e.g. molar, canine, bicuspid, incisor and thelike) as the actual tooth image it is intended to model, and may also bethe same numbered tooth as the actual patient tooth, using conventionaltooth numbering and identification systems.

In patient tooth image module 106, data sets representing a patient'stooth crown may be generated by various techniques for creating a toothcrown image, such as those disclosed in U.S. Pat. No. 6,685,469,assigned to Align Technology, Inc. (the “469 Patent”), hereinincorporated by reference, in its entirety, for all purposes, or suchmodeling processes known and provided under the brands INVISALIGN® andCLINCHECK® that are available from Align Technology, Inc. of SantaClara, Calif.

The creation of the complete tooth model 112 in complete tooth modelmodule 110 may be realized by combining or merging the data from toothgeometry module 102 and patient tooth image module 106, such as by acomputer algorithm within a tooth model system, for the creation of acomplete tooth, with such processes being applied to any or all teethwithin the patient.

As shown in FIG. 1C, exemplary modeling methods may be conducted withone or more computer-based systems, for example, a system 120 configuredfor storing patient data and generic tooth data. Also, a tooth modelingsystem 122 configured for executing generic tooth module 102 and patienttooth crown module 106 and for merging data and information generatedfrom modules 102 and 106 to generate complete tooth model 112 incomplete tooth model module 110. A system 124 may be configured forfacilitating any other conventional orthodontic treatment applications,such as methods or processes for tracking teeth movement and position,evaluating gingival effects, or any other orthodontic treatment processfrom pre-treatment to final stages, or any stages in between.

Systems 120, 122 and/or 124 may include one or more microprocessors,memory systems and/or input/output devices for processing modeling dataand information. To facilitate modeling of a patient crown, toothmodeling system 122 may include one or more software algorithmsconfigured for generating complete tooth model 112 and/or performingother functions set forth herein (e.g., receiving data from a scanner126).

FIG. 2 is a flow diagram illustrating an exemplary computer-implementedprocess 200 for modeling of a complete tooth crown model of a patient'spartially blocked or unexposed crown surfaces. Process 200 includes amethod 202 for generating a generic tooth crown model, a method 204 forgenerating a patient tooth crown model, excluding partially blocked orunexposed crown surfaces, and a method 206 for generating a completetooth crown model through a combination of a morphed generic tooth crownmodel with a corresponding patient partially complete tooth crown model.

Generic tooth modeling method 202 provides a reference for constructionof generic tooth 104 (FIG. 1B), which may include both a root and acrown for a particular tooth, if desired. In one embodiment, generictooth modeling method 202 includes the generation of a generic toothmodel template 208, auto-segmenting of a generic crown from the genericroot, if needed, within the generic tooth model 210, and automaticcreation of landmarks on the generic crown 212.

Generation of a generic tooth model template (208) may be configured tofacilitate the creation of landmarks on the generic tooth model to allowfor merging with the patient tooth crown model. For example, in order togenerate adequately distributed landmarks and to accurately segment thecrown from the tooth, the setup of generic tooth data is provided togenerate a generic tooth template as shown in FIG. 3A.

FIG. 3 A illustrates a process 300 for generating a generic tooth modeltemplate (208) in accordance with one embodiment. Process 300 includesthe acquisition of data from a physical tooth model (302), such as atypodont, the decimation of tooth model data (304), the creation of ageneric tooth model coordinate system (306), the construction of ageneric tooth digital model (308), the identification of gingival curves(310) and the creation of template file(s) associated with the generictooth model (312).

The acquisition of data from a physical tooth model (302) may includethe scanning of a standard typodont or any other three-dimensionalmodels for demonstrating alignment of teeth within a patient to generatethree-dimensional digital template data.

In one embodiment, a contralateral pair of a partially represented crownmay be used to provide the generic tooth model. For example, as shown inFIG. 3C, tooth 314 has a contralateral pair—contralateral tooth316—which has substantial bilateral symmetry (mirror image symmetry) totooth 314. Thus, if a digital tooth image created from tooth 314 had apartially blocked or unexposed surface, then contralateral tooth 316 maybe scanned and the digital data “mirrored” to provide a substantiallysymmetric tooth to tooth 314 to be used as the generic tooth model inaccordance with the present invention.

In other embodiments, a scanned tooth having similar dentition or ascanned tooth having similar dentition, but from a different patient,may be used to provide the generic tooth model.

Such typodont or models that are used for scanning may include both anexemplary root and crown for a single tooth or multiple roots and teeth.In addition, such typodont or generic models may be based on differentconfigurations of teeth, for example, different sizes, shapes, and/orcaps, different types of teeth, such as molars, bicuspids or canines,and/or different occlusal patterns or characteristics, for example,overbite, underbite, skewed or other like misalignment patterns.

As such, generic models for any type of teeth characteristic or type maybe provided and used, allowing great flexibility in specializing fordifferent teeth structures, occlusal patterns and characteristics of apatient. In addition, any conventional devices, systems and/or methodsfor the scanning of physical models, such as typodonts, to generate datamay be used, such as known techniques for generating initial digitaldata sets (IDDS), including that set forth in U.S. Pat. No. 6,217,325,assigned to Align Technology, Inc., which is herein incorporated byreference, in its entirety, for all purposes.

To reduce the amount of data and/or filter out any undesirable dataafter such acquisition of data from the typodont or generic tooth model,the decimating of data (304) may be conducted, such as the removal ordeletion of data or otherwise the finding of optimal data values throughthe elimination at a constant fraction of the scanning data; however,the decimating of data (304) may also be omitted or otherwise replacedby any filtering or data enhancement techniques.

Whether or not the scanned data is decimated, the developing of ageneric tooth coordinate system (306) may be undertaken, such as tosetup or develop a generic tooth coordinate system as illustrated inFIG. 3B. The coordinate system may be set-up automatically and/oradjusted manually, using any conventional or later developed techniquesfor setting up coordinate systems of an object.

Upon generation of a coordinate system for a generic tooth, theconstructing of a digital generic tooth model (308) including root andcrown may be conducted for an individual tooth and/or two or more teeth.Such constructing of digital tooth models may include any methodology orprocess for converting scanned data into a digital representation. Suchmethodology or processes may include, for example, those disclosed inU.S. Pat. No. 5,975,893, entitled “Method and System for IncrementallyMoving Teeth” assigned to Align Technology, Inc., herein incorporated byreference, in its entirety, for all purposes. For example, withreference to an overall method for producing the incremental positionadjustment appliances for subsequent use by a patient to reposition thepatient's teeth as set forth in U.S. Pat. No. 5,975,893, as a firststep, a digital data set representing an initial tooth arrangement isobtained, referred to as the IDDS.

After construction of the generic tooth digital model (308), theidentifying of the gingival curve (310) may be conducted to identify thegum lines and/or root association. Such identification may include anyconventional computational orthodontics methodology or process foridentification of gingival curves, now known or hereinafter derived. Forexample, the methodologies and processes for identification of gingivalcurves may include those disclosed in U.S. Pat. No. 7,040,896, entitled“Systems and Methods for Removing Gingiva From Computer Tooth Models”,and assigned to Align Technology, Inc. (the “896 Patent”) and U.S. Pat.No. 6,514,074, entitled “Digitally Modeling the Deformation ofGingival”, and assigned to Align Technology, Inc. (the “074 Patent”),which are herein incorporated by reference, in their entirety, for allpurposes, and the various patents disclosed in the '896 and '074patents. In the '896 Patent, for example, such a process foridentification of gingival curves may include a computer-implementedmethod for separating a tooth from an adjacent structure, such as agingiva, by defining a cutting surface, and applying the cutting surfacebetween the tooth and the structure to separate the tooth in a singlecut.

Having constructed the digital generic tooth model (308) and identifiedthe gingival curve (310), one or more generic tooth template files maybe created (312), such as the exemplary generic teeth templateillustrated in FIG. 3C including substantially a complete set of teethof a patient. Such generic teeth templates may then be used to allow forsegmenting of crowns and landmark distribution on the generic teeth. Inaddition, such generic teeth templates may be used for one or moretreatments, and/or replaced or updated with other generic teethtemplates as desired. Moreover, such generic teeth templates may becreated and/or stored for later use, and may be configured for variousdifferences in patients, such as for children-based templates andadult-based templates, with the ability to have a plurality of templatesthat are specially created for the different types of teeth and relatedcharacteristics, sizes, shapes, and occlusal patterns or other features.

Referring again to FIG. 2 , after generic teeth templates have beengenerated, automated segmenting of a generic crown from the generic rootwithin the generic tooth template (210) may be conducted to prepare thegeneric tooth template for landmark creation. In this process, the crownportion of the generic tooth template may be parceled out and/oridentified to allow mapping during landmark processes.

For the generic tooth, the crown geometry may be extracted from thegeneric tooth model. After such extraction or segmentation, a crown meshmay be generated. For example, with reference to FIGS. 5A and 5B, aprocess 500 for automated crown mesh generation may include theconstruction of a 3-D spline curve (502), where control points on thetransition area between the tooth crown and root are used, such as thatillustrated in FIG. 5B. Next, the projection of the 3-D spline curve onthe tooth mesh model (504) may be conducted. A calculation of theintersection between the projected curve and the edges of triangle facesof the mesh (506) may then be made to facilitate the construction of newtriangles (508). In this process, the three original vertices of theintersected triangle and the two intersection points may be used toconstruct three new triangles, such as by use of the Delaunaytriangulation's max-min angle criterion. After such construction, there-triangulation of the old intersected triangle and replacing that oldtriangle with the three newly generated triangles (510) may beconducted. Upon re-triangulation and replacement, the generation of anew crown mesh model (512) may be realized by removing all the facesbelow the projected curve, resulting in a segmented generic tooth crown.Processes 502, 504, 506, 508, 510 and 512 may be provided through anyknown conventional techniques for providing such functions, orhereinafter devised.

Referring again to FIG. 2 , once the crown of the generic tooth templatehas been segmented, automated creation of landmarks on the generic crown(212) may be performed prior to morphing with the patient tooth crownmodel. In accordance with one embodiment, with reference to FIGS. 4A-4D,landmarks may be created on a crown sphere (402) and then the landmarksmay be projected onto a crown surface (404). For example, a tooth crownmay be mapped to a sphere by central projection, as illustrated in FIG.4B. The landmarks may be created on the sphere through appropriatedistribution on each of a plurality of cross-sections, for example,cross-sections through the Z-axis, perpendicular to the X-Y plane. Asillustrated in a representative cross-section shown in FIG. 4C, aplurality of landmarks 406 may be created on a sphere 410 withappropriate distribution. The number of landmarks 406 may be determinedthrough parameters such as the number of planes to be considered whilesweeping through the Z-axis, and the number of points selected for eachplane.

Once landmarks 406 are created on crown sphere 410 (402), landmarks 406may be projected onto the crown surface, such as projected landmarks 408projected onto the crown surface in FIG. 4C, and projected landmarks 408illustrated in FIG. 4D that include projected landmarks 408 projectedonto a scan of a patient's crown 420 and a generic tooth crown 430. Suchan automated generation may be facilitated by one or more algorithmswithin a tooth modeling system, and may be computed for each patienttooth and generic tooth.

Note that a portion of the patient's crown surface image that has beenpartially blocked or has not yet erupted past the gingival line may beprojected as a partial 3-D image. Thus, projected landmarks 408 are notdirectly projected to the patient's crown surface, but rather to alocation that approximates the patient's crown surface as describedbelow. The plurality of projected landmarks 408 on generic tooth crown430 and the corresponding projected landmarks 408 on the patient toothcrown 420 may be used for calculating the morphing function as alsodescribed below.

Referring again to FIG. 2 , method 204 for generating a patient toothcrown model may include the generation of an initial patient tooth modelwith at least a portion of the tooth structure missing (214), whichincludes generation of a crown tooth model having at least a portion ofthe tooth structure missing, automated detection of the remaining crowngeometry (216) and the automated creation of landmarks on the patientcrown tooth model (218). Generating the crown tooth model (214) may berealized by various known methods and techniques, including variousconventional scanning techniques used in computational orthodontics forcreating IDDS and the like.

For example, such an IDDS may be derived from the above methods and/oras set forth in U.S. Pat. No. 6,217,325, also assigned to AlignTechnology, Inc. In an exemplary embodiment, to obtain an IDDS, thepatient's teeth may be scanned or imaged using well known technology,such as X-rays, 3D X-rays, computer-aided tomographic images or datasets, magnetic resonance images, and the like. Methods for digitizingsuch conventional images to produce data sets useful in the presentinvention are well known and described in the patent and medicalliterature.

Upon generation of the crown tooth model, automatic detection of thecrown geometry (216) may be conducted to prepare the tooth model forcreation of landmarks. For the patient tooth model, the crown geometrymay be segmented from the entire tooth using any conventional processfor segmentation of crowns from teeth. In one embodiment, the occlusalpart of patient's crown geometry is available from the initial patienttooth model. An appropriate template may be selected from a library ofcrowns of the same tooth type based on the relative position of theocclusal features. The template selected may be scaled and positioned sothat the missing portion of the patient's crown may be approximated asclosely as possible. A threshold or envelope is established. Thus,points on the patient's tooth model that are a distance outside of theestablished threshold are considered as not belonging to the crown.Accordingly, projected landmarks may be placed only on the portions ofthe patient's crown that fall within the threshold. Only thecorresponding landmarks are placed on the generic crown model of thesame tooth. These landmarks are used for the subsequent morphing.

Thus, upon detecting the crown geometry, the automated creation oflandmarks on the patient crown tooth model may be provided, such as thetechniques (212) used on the generic crown model, for example, thoseillustrated in FIGS. 4A-4D.

Upon generation of the generic tooth model (202) and the crown toothmodel (204), generation of the complete tooth model (206) may beconducted through combining or merging of the generic tooth model withthe corresponding patient tooth crown model.

In one embodiment, a method for generating a complete tooth model (206)may include calculating the morphing function (220), applying themorphing function to the generic crown model to calculate a morphedgeneric crown model (222), stitching the morphed generic crown model tothe patient crown model (224), smoothing the morphed crown-to-patientcrown transition areas (226), thereby completing the missing toothstructure, and conducting interactive adjustment of the completedpatient crown, if necessary (228). Such processes may be completelyconducted for individual teeth before proceeding to any other teeth,conducted concurrently, or any other combination thereof. Morespecifically, an initial morphing function, which is used to determine amorphed central axis, may be calculated using crown landmarks from thepatient crown tooth model and a generic crown model or a digitallymirrored contralateral tooth model. A central axis of the generic crownmodel or the digitally mirrored contralateral tooth model is determinedand repositioned so as to be tangential to the morphed central axis. Therepositioned central axis is then scaled to be substantially equal tothe morphed central axis in a direction along a z-axis (see FIG. 4B). Afinal morphing function is then calculated through use of the crownlandmarks from the generic crown model or the digitally mirroredcontralateral tooth model and the patient crown model, and this finalmorphing function is applied to the generic crown model to calculate amorphed generic crown model.

In one embodiment, a thin-plate spline may be used to calculate themorphing function (220) by using the projected landmarks 408 (FIG. 4C).Use of such a thin-plate spline may minimize the deformation energyeffects, for example, minimize the degree or extent of bent in theresulting surface between created landmarks 408. The deformation energyis defined as:

${\int{\int_{R^{2}}\left( \frac{\partial^{2}f}{\partial^{2}x^{2}} \right)^{2}}} + {2\left( \frac{\partial^{2}f}{{\partial x}{\partial y}} \right)^{2}} + {\left( \frac{\partial^{2}f}{\partial^{2}y^{2}} \right)^{2}{dxdy}}$

Once the morphing function is calculated (220), the patient crown modelmay be calculated (222), such as by applying the morphing function onthe generic tooth crown model.

After calculation of the patient tooth crown model (222) throughmorphing of the generic tooth crown model, the patient crown model maybe stitched to the generic crown model to generate the complete 3-Dtooth model (224). Generally, stitching occurs along the boundary of themissing crown surface of the patient's tooth model and the generic toothcrown model. To facilitate stitching, the generic crown mesh and thepatient crown mesh are combined or merged. For example, with referenceto FIG. 6 , the stitching process includes the projecting of 3-D loopsonto the X-Y plane (602). Since the projected loops are homogeneous to acircle, the loop vertices may be re-sorted by angle to construct amerged loop (604). Next, re-triangulation of the generic crown mesh andthe patient crown mesh may be conducted (606). Upon re-triangulation,the generic crown mesh and the patient crown mesh may be merged (608) toobtain a topologically correct complete tooth crown mesh.

After stitching (224), the transition areas of the complete tooth modelmay be smoothed (226) to improve the model, for example, using asmoothing algorithm. The smoothing algorithm may operate as a filter toessentially remove “noise” from the stitched points within thetransition area. In one embodiment, the smoothing algorithm may identifyor target a first point, then observe neighboring points to tweak orotherwise adjust the first point to smooth out the stitching. Thealgorithm may be conducted for each tooth within the patient. Such analgorithm may also include various formats and structures for providingthe smoothing function

After generation of the complete crown model, the generated crown shapemay vary from the actual crown shape due to the individual features ofthe patient. With reference again to FIG. 1A in accordance with anexemplary embodiment, further adjustment of the complete crown model forthe tooth may be provided through detailed adjustment module 114. Forexample, additional patient tooth crown information regarding featuresor characteristics of the patient's actual crown, such as may beobtained from X-ray imaging information provided from radiograph 116,may be used by tooth modeling system 122 to address the variations incrown shape between the generic tooth crown and an the actual toothcrown shape for a patient so as to yield a tooth shape on complete toothmodel 112 which more closely approximates the actual tooth shape of theactual teeth.

Such additional actual tooth crown information may include variousformats and generated in various manners. For example, X-ray imaginginformation may include panoramic, periapical, bitewing, cephalometricor other like information, for facilitating further detailed modeling.In addition, since such X-ray imaging information generally comprises a2D image, the X-ray information may be considered approximately as a 2Dprojection from the facial side to the lingual side. As a result, thefurther detailed adjustment is based on one-view information, where thealgorithm makes the modeled tooth shape coincide with the actual toothshape based on such one-view information.

In one embodiment, as in FIG. 7A, a method 700 for detailed adjustmentmodeling may begin with the projection of the complete crown model, forexample, one derived after combining/merging (206) of method 200, on asingle plane, whose normal is from a tooth's facial side to a tooth'slingual side (702). Next, the contour of the complete crown may becalculated (704) and defined, such as the tooth crown contour Aillustrated in FIG. 7B. The corresponding patient tooth crown may beidentified from the X-ray information, such as from panoramic X-rayimage (706), and the contour of the corresponding tooth crown may alsobe calculated from that X-ray image (708) and defined, such as the toothcrown contour B illustrated in FIG. 7C. Any conventional methodology orprocess for calculation and/or determination of contours may be readilyused for determining the contours of tooth crown A and tooth crown B.

Next, the scaling in size between the complete tooth crown contour(contour A), and the corresponding patient tooth crown contour (contourB) may be determined (710), and then the corresponding patient toothcrown contour may be scaled to have the same crown contour as thecomplete tooth crown contour (712).

In accordance with an alternative embodiment, instead of scaling thepatient tooth crown contour to the complete tooth crown contour (712), athin-plate spline based morphing function may be used to deform thecorresponding patient tooth crown contour to the complete tooth crowncontour. For example, the morphing function may be calculated by thelandmarks on the corresponding patient tooth crown contour and completetooth crown contour. Landmarks may then be generated (714) on thecomplete tooth contour (contour A), and the corresponding patient toothcontour (contour B), such as illustrated with reference to FIGS. 7D and7E. Based on the generated landmarks, and the calculation of themorphing function, the complete tooth contour may be morphed onto aprojection plane (716), such as illustrated in FIG. 7F. Such morphingmay be conducted through similar processes as disclosed inmorphing/combining process 206, for example, by calculating a morphingfunction by landmarks (220) and applying the morphing function on thegeneric tooth crown (222). Accordingly, a complete tooth crown model forany one and/or all teeth of a patient, adjusted through an accounting ofa patient's individual and/or specialized features and characteristics,may be realized.

The present invention has been described above with reference to variousexemplary embodiments. However, those skilled in the art will recognizethat changes and modifications may be made to the exemplary embodimentswithout departing from the scope of the present invention. For example,the various operational steps, as well as the components for carryingout the operational steps, may be implemented in alternate waysdepending upon the particular application or in consideration of anynumber of cost functions associated with the operation of the system,for example, various of the component and methodologies and/or steps maybe deleted, modified, or combined with other components, methodologiesand/or steps. Moreover, it is understood that various of the methods andsteps disclosed herein, such as generating of IDDS, construction of 3Dspline curves, identifying gingival curves or other processes may alsoinclude any other conventional techniques, or any later developedtechniques, for facilitating such methods and steps. These and otherfunctions, methods, changes or modifications are intended to be includedwithin the scope of the present invention, as set forth in the followingclaims.

What is claimed is:
 1. A system for modeling a complete patient tooth tofacilitate orthodontic treatment of a patient, the system comprising: ascanner operable to capture a scanned image of at least a portion of asurface of a first crown component of a first patient tooth, and togenerate scanned image data representing only a partial portion of thesurface of the first crown component; memory configured to store alibrary of digital tooth templates; and a computer processor operativelycoupled to the scanner and to the memory, the computer processor beingconfigured to implement a computer-implementable method comprising:receiving the scanned image data from the scanner; creating a digitaldata set representing the scanned image data; creating a first digitallandmark pattern for the digital data set representing the scanned imagedata; creating, in the stored library of digital tooth templates, animage of a tooth that is a contralateral tooth to the first patienttooth; using the digital data set representing the scanned image datato, select, from the library of digital tooth templates, a digital toothtemplate that includes a digital crown portion corresponding to thescanned image data; creating a second digital landmark pattern for thedigital crown portion of the selected digital tooth template, the seconddigital landmark pattern being derived from an image of a second tooth,wherein the image of the second tooth comprises a digitally-mirroredmodel of the contralateral tooth to the first patient tooth; using thefirst and second digital landmark patterns to calculate an initialmorphing function; using the initial morphing function to determine amorphed central axis; repositioning a central axis of the digital crownportion of the selected digital tooth template so as to be tangential tothe morphed central axis; scaling the repositioned central axis of thedigital crown portion of the selected digital template tooth to besubstantially the same as the morphed central axis in a direction alonga z-axis to create a scaled digital crown portion with a scaled seconddigital landmark pattern; using the first digital landmark pattern andthe scaled second digital landmark pattern from the scaled digital crownportion to calculate a final morphing function; applying the finalmorphing function to the scaled digital crown portion of the selecteddigital tooth template to create a morphed digital tooth crown model;and merging the morphed digital tooth crown model with the digital dataset to generate a complete digital patient tooth crown model.
 2. Thesystem of claim 1, wherein the computer-implementable method furthercomprises interactively adjusting the morphed digital tooth crown modeland the complete digital patient tooth crown model after the merging hasbeen performed.
 3. The system of claim 1, wherein thecomputer-implementable method further comprises calculating the finalmorphing function using a thin-plate spline.
 4. The system of claim 1,wherein the scanner is operable to scan a portion of a gingival curve ofthe patient, and wherein the scanned image data includes datarepresenting the scanned portion of the gingival curve of the patient.5. The system of claim 1, wherein the complete digital patient toothcrown model includes transition areas resulting from the merging of themorphed digital tooth crown model with the digital data set, and whereinthe computer-implementable method further comprises smoothing thetransition areas of the complete digital patient tooth crown model. 6.The system of claim 1, wherein the computer-implementable method furthercomprises generating the complete digital patient tooth crown model bygenerating an initial digital patient tooth crown model representing thescanned image, and scaling and positioning the digital crown portionrelative to the initial digital patient tooth crown model so as toapproximate the complete digital patient tooth crown model.
 7. Thesystem of claim 1, wherein the computer-implementable method furthercomprises creating the first digital landmark pattern for a firstdigital crown mesh derived from the digital data set representing thescanned image data, and creating the second digital landmark pattern fora second digital crown mesh derived from the digital crown portion ofthe selected digital tooth template.
 8. A system for modeling a completepatient tooth to facilitate orthodontic treatment of a patient, thesystem comprising: a scanner operable to surface capture a scanned imageof at least a portion of a surface of a first crown component of a firstpatient tooth, and to generate scanned image data representing only apartial portion of the surface of the first crown component; memoryconfigured to store a library of digital tooth templates; and a computerprocessor operatively coupled to the scanner and to the memory, thecomputer processor being configured to implement acomputer-implementable method comprising: receiving the scanned imagedata; creating a digital data set representing the scanned image data;creating a first digital landmark pattern for the digital data set;using the digital data set representing the scanned image data toselect, from the library of digital tooth templates, a digital toothtemplate that includes a digital crown portion corresponding to thescanned image; creating a second digital landmark pattern for thedigital crown portion of the selected digital tooth template; using thefirst and second digital landmark patterns to calculate an initialmorphing function; using the initial morphing function to determine amorphed central axis; repositioning a central axis of the digital crownportion of the selected digital tooth template so as to be tangential tothe morphed central axis; scaling the repositioned central axis of thedigital crown portion of the selected digital template tooth to besubstantially the same as the morphed central axis in a direction alonga z-axis to create a scaled digital crown portion with a scaled seconddigital landmark pattern; using the first digital landmark pattern andthe scaled second digital landmark pattern from the scaled digital crownportion to calculate a final morphing function; applying the finalmorphing function to the scaled digital crown portion of the selecteddigital tooth template to create a morphed digital tooth crown model;and merging the morphed digital tooth crown model with the digital dataset representing the scanned image data of the first patient tooth togenerate a complete digital patient tooth crown model.
 9. The system ofclaim 8, wherein the computer-implementable method further comprisesinteractively adjusting the morphed digital tooth crown model and thecomplete digital patient tooth crown model after the merging has beenperformed.
 10. The system of claim 8, wherein the computer-implementablemethod further comprises calculating the final morphing function using athin-plate spline.
 11. The system of claim 8, wherein the scanner isoperable to scan a portion of a gingival curve of the patient, andwherein the scanned image data includes data representing the scannedportion of the gingival curve of the patient.
 12. The system of claim 8,wherein the complete digital patient tooth crown model includestransition areas resulting from the merging of the morphed digital toothcrown model with the digital data set representing the scanned imagedata, and wherein the computer-implementable method further comprisessmoothing the transition areas of the complete digital patient toothcrown model.
 13. The system of claim 8, wherein thecomputer-implementable method further comprises: generating the completedigital patient tooth crown model by generating an initial digitalpatient tooth crown model representing the scanned image; and scalingand positioning the digital crown portion relative to the initialdigital patient tooth crown model so as to approximate the completedigital patient tooth crown model.
 14. The system of claim 8, whereinthe computer-implementable method further comprises: creating the firstdigital landmark pattern for a first digital crown mesh derived from thedigital data set to generate a complete digital patient tooth crownmodel the scanned image; and creating the second digital landmarkpattern for a second digital crown mesh derived from the digital crownportion of the selected digital tooth template.